'\" te
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.TH MOUNT_TMPFS 8 "Mar 18, 2015"
.SH NAME
mount_tmpfs \- mount tmpfs file systems
.SH SYNOPSIS
.LP
.nf
\fBmount\fR [\fB-F\fR tmpfs] [\fB-o\fR \fIspecific_options\fR] [\fB-O\fR] \fIspecial\fR \fImount_point\fR
.fi

.SH DESCRIPTION
.LP
\fBtmpfs\fR is a memory based file system which uses kernel resources relating
to the \fBVM\fR system and page cache as a file system.
.sp
.LP
\fBmount\fR attaches a \fBtmpfs\fR file system to the file system hierarchy at
the pathname location \fImount_point\fR, which must already exist. If
\fImount_point\fR has any contents prior to the \fBmount\fR operation, these
remain hidden until the file system is once again unmounted. The attributes
(mode, owner, and group) of the root of the \fBtmpfs\fR filesystem are
inherited from the underlying \fImount_point\fR, provided that those attributes
are determinable. If not, the root's attributes are set to their default
values. The mode may also be overridden by the \fBmode\fR mount option, which
takes precedence if set.
.sp
.LP
The \fIspecial\fR argument is usually specified as \fBswap\fR but is in fact
disregarded and assumed to be the virtual memory resources within the system.
.SH OPTIONS
.ne 2
.na
\fB\fB-o\fR \fIspecific_options\fR\fR
.ad
.RS 23n
Specify \fBtmpfs\fR file system specific options in a comma-separated list with
no intervening spaces. If invalid options are specified, a warning  message is
printed and the invalid options are ignored. The following options are
available:
.sp
.ne 2
.na
\fB\fBremount\fR\fR
.ad
.sp .6
.RS 19n
Remounts a file system with a new size. A size not explicitly
set with \fBremount\fR reverts to no limit.
.RE

.sp
.ne 2
.na
\fBmode=\fIoctalmode\fR\fR
.ad
.RS 19n
The \fImode\fR argument controls the permissions of the \fBtmpfs\fR mount
point.  The argument must be an octal number, of the form passed to
\fBchmod\fR(1).  Only the access mode, setuid, setgid, and sticky bits (a mask
of \fB07777\fR) may be set.  If this option is not provided then the default
mode behaviour, as described above, applies.
.RE

.sp
.sp
.ne 2
.na
\fBsize=\fIsz\fR\fR
.ad
.RS 19n
The \fIsz\fR argument controls the size of this particular \fBtmpfs\fR file
system. If the argument is has a `k' suffix, the number will be interpreted as
a number of kilobytes. An `m' suffix will be interpreted as a number of
megabytes. A `g' suffix will be interpreted as a number of gigabytes. A `%'
suffix will be interpreted as a percentage of the swap space available to the
zone. No suffix is interpreted as bytes. In all cases, the actual size of
the file system is the number of bytes specified, rounded up to the physical
pagesize of the system.
.RE

.sp
.ne 2
.na
\fB\fBxattr\fR | \fBnoxattr\fR\fR
.ad
.RS 19n
Allow or disallow the creation and manipulation of extended attributes. The
default is \fBxattr\fR. See \fBfsattr\fR(7) for a description of extended
attributes.
.RE

.RE

.sp
.ne 2
.na
\fB\fB-O\fR\fR
.ad
.RS 23n
Overlay  mount. Allow the file system to be mounted over an existing mount
point, making the underlying file system inaccessible. If a mount is attempted
on a pre-existing mount point without setting this flag, the mount will fail,
producing the error: \f(CWdevice busy\fR.
.RE

.SH FILES
.ne 2
.na
\fB\fB/etc/mnttab\fR\fR
.ad
.RS 15n
Table of mounted file systems
.RE

.SH SEE ALSO
.LP
.BR mkdir (2),
.BR mount (2),
.BR open (2),
.BR umount (2),
.BR tmpfs (4FS),
.BR mnttab (5),
.BR attributes (7),
.BR fsattr (7),
.BR mount (8)
.SH NOTES
.LP
If the directory on which a file system is to be mounted is a symbolic link,
the file system is mounted on the directory to which the symbolic link refers,
rather than on top of the symbolic link itself.
